Resilient traction rail joint insulator



Feb. 23, 1954 N. K. MOSES 2,670,136

RESILIENT TRACTION RAIL JOINT INSULATOR Filed Oct. 22, 1948 2 Sheets-Shet l INVENTOR.

Heisonifflllos BY a ATTO NEYS Feb. 23, 1954 N. K. MOSES 2,670,136

RESILIENT TRACTION RAIL JOINT INSULATOR Filed Oct. 22, 1948 2 Sheets-Sheet 2 /6 INVENTOR.

flelsmmlloscs TTOIZNEYS Patented Feb. 23, 1954 RESILIENT TRACTION RAIL JOINT INSULATOR Nelson K. Moses, Ashtabula, Ohio, assignor to Railroad Rubber Products, Inc, a Florida corporation Application October 22, 1948, Serial No. 55,949

4 Claims.

This invention relates to a device for electrically insulating a rolling stock support rail joint.

Incident to railway operation, particularly the operation of signals and switches, use is made of sections of track as conductors in the electrical circuits. The circuits are, in general, local and therefore the track section so employed must be isolated from the track as a whole.

In dealing with this problem heretofore the provisions made for insulation have followed conamounting to a matter of life and death, as is i well known. Although the shortcomings of the conventional rollin stock support rail joint insulators have been recognized for a long time no major improvements thereon have been advanced, but rather the solution has consisted in vigilance and constant maintenance.

I have found that whereas the simple interposition of insulating members to mask only the points of metallic contact is reasonable as an initial installation, it does not take cognizance of certain important afa-ctors of environment during use which bring about conditions resulting in failure. For instance, it is not only common but inevitable for electrically conducting material to accumulate within the confines of the supposedly insulated joint. This is not only brought about by weather conditions but also by the air disturbances caused by rolling railway stock. The joints, as they now exist, form a natural trap for flying particles, leading to early electrical leakage at the joint. These particles may comprise coal dust, dust from wear in the metal parts, both from the rail and the rolling stock, notably brakes, and material from other sources. While in an open-air railway joint, the condition may be somewhat alleviated by leakage of accumulated dust into the ground or otherwise away from the joint during a rainfall, the problem remains particularly acute in underground installations such as subway systems.

It is a further shortcoming of the known insulators that they partake of physical breakdown in unreasonably short periods due to vibration fatigue and other similar causes.

I have found that by the employment of a sleeve of rubber or rubber-like material, which not only electrically but mechanically masks the joint, all of the above enumerated defects are satisfactorily abated while a considerably longer life is accorded the installation and at the same time a desirable mechanical cushioning is achieved and the noise level is appreciably reduced.

It is therefore an object of the invention to provide an electrical insulator for a rolling stock support rail joint which shall additionally preclude the entrance of foreign matter into all parts of the joint. More particularly it is an object to provide such an insulator which is adapted to snugly engage all metal portions in the region of the joint, further objects being to achieve the foregoing objects while providing a rolling stock support rail joint installation with long life and one which cushions shocks and abate-s noise.

These and other ends which will be in part manifest and in part made apparent as the description proceeds are attained by the invention, one embodiment of which is described in the accompanying specification and illustrated in the drawings in which:

Fig. 1 is a top plan view of an insulated rolling stock support rail joint according to the invention,

Fig. 2 is a side view of Fig. 1,

Fig. 3 is a perspective view of my novel insulator element along with an insulating rail spacer,

Fig. 4 is a section taken on the line 4-4 of Fig. 2, and

Fig. 5 is a section taken on the line 5-5 of Fig. 2.

Referring to the drawings by characters of reference, there is shown, in Fig. l, a pair of rolling stock support rail sections l, 2 with their inner,

juxtaposed ends closely adjacent and separated by a spacer 3 of rubber having the same sectional profile as the track sections.

The adjoining ends of the rolling stock support rails are supported between a pair of identical but oppositely disposed joint bars 4, 5 which are secured to the ties 5 as by screw spikes 6 with head supports 1, the joint bars being secured to the rolling stock support rail sections by bolts 8 passing through the web of the rail sections.

The joint bars conventionally employed have an inner sectional profile corresponding roughly to the outer profile of a rolling stock support rail, but depart somewhat from this shape as shown at 9 below the middle of the bolt 8, and at H! adjacent the base flange of the rail. Also, there is considerable clearance between the lowermost, inner portions l2 of the joint bar. Standard joint bars, of necessity have some clearance in this region and the gap is augmented when insulating liners are employed. It is in this opening that the condition of particle infiltration is most pronounced.

In the prior art constructions sheets of fibre board or other similarly untractable material have been inserted between the joint bars and the rolling stock support rail, in the mistaken belief that perfunctory separation of conductors was the only requirement as in the case of most electrical installations. This and similar materials are not adapted to closely mate with the surface of the rail, especially at the sharp bend at the outer edge of the bottom flange, which latter region, indicated at It? is equally vulnerable to entrance of foreign matter as is the region at l2.

My novel insulator comprises a pair of liners I3, I4 of resilient rubber or rubber-like material. These are preferably molded to the shape shown in Figs. 3, 4 and 5 to provide a glove fit between the joint bar and rolling stock support rail to seal off the passages by which particles could infiltrate to the critical regions.

It will be noted that right hand liner i4 is longer on the bottom flap I51 than is the bottom flap iii of liner l3. This provides an efiective closure for the passage between the portions 42 of the joint bars. by forming the entire liner as one piece, but such construction would involve difiiculties in passing the liner beneath the rail. Also the liner is readily adapted to close the region ill.

I have found that if the liner completely fills the opening at the region 9, not only is infiltration cut off to the neighborhood of the bolts but that the bolts require tightening less often than in assemblies with liners heretofore used, probably because of the reduction of vibration. The region at E9 is not so critical for infiltration, and it may be desirable to leave a clearance at this point to allow spread of the liner and so enhance the tightness of the liner fit. However, the region Hi may also be completely filled by the liner if deemed necessary or desirable for an reason.

As shown, the liners: have integral bushings H, which snugly engage in the bolt openings of the joint bars; veniently cut from tubing and assembled in holes in the liners.

The joint bars are further insulated exteriorly by rubber strips or washer bars 58 having holes to receive bolts 8, and steel washer bars [9 are This result could be achieved However, these may be con- Number 4 beneath the base of the rails bolted to the rails on each side thereof in spaced relationship thereto, the bolts being insulated from the joint bars, the improvement which comprises integral molded preformed resilient bodies formed solely of rubber interposed between each side of said rails and said joint bars and approximately coextensive with the joint bars, each of said rubber bodies having openings therein at spaced points along their lengths to receive the bolts employed to hold the joint bars and rails together, said rubber bodies being maintained in stressed condition in intimate contact with the outer surface of said rolling stock supporting rails along the underside of the head of the rails, the vertical web of the rails, the top surface of the base of the rails and beneath a substantial portion of the underside of the rails and with the rail facing surface of the joint bars opposite the.

aforementioned parts of the rail to com letely fill the space therebetween including the irregularities of the surfaces of the rails and joint bars, except at the rail base edges, under the pressure imposed by the bolts which pass through the joint and hold the same together, the relationship of rails, joint bars and rubber bodies being such as to provide the rubber bodies with unrestrained ends to permit the spreading of the rubber bodies under the force placed upon them by the bolts whereby the bolts are maintained under tension by means of the resilient action of the rubber bodies.

2. An electrically insulating rolling stock supporting rail joint as recited in claim 1 in which the insulation between the bolts and the joint bars is formed solely of rubber and is integral with the said rubber bodies.

3. An electrically insulating rolling stock supporting rail joint as recited in claim 1 in which the said substantial portions added together are less than the total width of the underside of the base of the rail to provide a small space between the lengthwise edges of the rubber bodies beneath the base of the rail.

' 4. An electrically insulating rolling stock supporting rail joint as recited in claim 3 in which the said small space is located oif center so that it does not overlie the space between the joint bars beneath the base of the rail.

NELSON K. MOSES.

References Cited in the file of this patent UNITED STATES. PATENTS Name Date 849,434 Stephens Apr. 9, 19 07 878,588 Wolhaupter. Feb. 11, 1908 879,878 Kohn Feb. 25, 1968 996,633 Forsyth July 4, 19.11 2,324,993 Kubaugh July 20, 19.43

FOREIGN PATENTS Number Country Date,

164,954 Great Britain June 23, 1921 618,758 Great Britain Feb. 25,1949 

